Electric motors having face type carbon commutators have become popular for use in fuel pump assemblies for organic fuels, such as methanol, propane and the like, and for hydrocarbon mixtures including organic fuels, the mixture commonly known as gasohol. The typical motor of the flat disk type includes an armature with a plurality of electrically conductive base metals electrically insulated from each other but solidly secured in a body portion formed of insulating material. Carbon based protective members are soldered to the base metal members after the base metal surface is passified with a layer of another metal to assure a good bond between the solder, carbon and other metal layer. See for example, U.S. Pat. Nos. 5,245,240; 5,255,426; 5,175,463; and 5,157,299.
Conventional motors fitted with disk or face type carbon based commutators are known to experience various technical problems and expensive processing due to their design, costly materials, and excessive manufacturing difficulties and steps. For example, since the alcohol or other oxygenated constituent corrodes copper, the copper seat or base must be completely encapsulated in non-corrosive materials. Some conventional commutators include the carbon elements soldered directly to copper, nickel or other metal or alloy commutators. Alternatively, in order to assure good electrical and mechanical contact between these parts, a silver layer based metal layer is first coated on the copper based metal facing the carbon layer in order to avoid the need to passify the carbon before soldering. In either case, the silver layer or the passification of carbon adds to the cost of manufacturing and the cost of parts.
During subsequent steps of motor manufacturing, the motor winding wire is placed within the tang profile during the assembly of the conventional armature. The work then moves to a fusing station where a fusing machine applies heat, current and pressure to the tang, burns off or vaporizes the wire insulation beneath the tang, and creates a fixed fusion joint between the deformed tang and wire combination. Because of the low melting point of the solder layer in the vicinity of the tang, it is known that the solder will often run or liquify in response to the highly heated tang and metallic commutator zones. Attempts to localize this heat solely to the tang material external of the carbon profile have only been partially satisfactory making manufacturing quality control difficult and/or expensive.
Although the carbon protective commutator has great application in gasohol fuel pumps and the like, it is known that motor maintenance requirements are greatly reduced with these carbon based commutator brush contacts. Accordingly, there is a need to apply the carbon based brush contact to other motor applications and designs such as a barrel type motor for various other applications.
As can be seen from the following summary and detailed description, the present invention solves the forgoing technical and manufacturing problems, avoids the use or need for soldering altogether, and provides other benefits and advantages in the design, operation, and manufacturing of motors of these types.